1
LTC1343
Software-Selectable
Multiprotocol Transceiver
s
Software-Selectable Transceiver Supports:
RS232, RS449, EIA-530, EIA-530-A, V.35, V.36,
X.21
s
NET1 and NET2 Compliant
s
Software-Selectable Cable Termination Using
the LTC1344
s
4-Driver/4-Receiver Configuration Provides a
Complete 2-Chip DTE or DCE Port
s
Operates from Single 5V Supply
s
Internal Echoed Clock and Loop-Back Logic
The LTC
®
1343 is a 4-driver/4-receiver multiprotocol trans-
ceiver that operates from a single 5V supply. Two LTC1343s
form the core of a complete software-selectable DTE or DCE
interface port that supports the RS232, RS449, EIA-530,
EIA-530-A, V.35, V.36 or X.21 protocols. Cable termination
may be implemented using the LTC1344 software-selectable
cable termination chip or by using existing discrete designs.
The LTC1343 runs from a single 5V supply using an internal
charge pump that requires only five space saving surface mount
capacitors. The mode pins are latched internally to allow sharing
of the select lines between multiple interface ports.
Software-selectable echoed clock and loop-back modes help
eliminate the need for external glue logic between the serial
controller and line transceiver. The part features a flow-
through architecture to simplify EMI shielding and is available
in the 44-lead SSOP surface mount package.
DTE Multiprotocol Serial Interface with DB-25 Connector
, LTC and LT are registered trademarks of Linear Technology Corporation.
s
Data Networking
s
CSU and DSU
s
Data Routers
D2
LTC1343
RTS
DTR
DSR
DCD
CTS
RL
D1
D3
D4
R1
R3
R4
R2
D2
LTC1343
LL
TXD
SCTE
TXC
RXC
RXD
TM
LL A (141)
TXD A (103)
TXD B
SCTE A (113)
SCTE B
RXC A (115)
RXC B
RXD A (104)
RXD B
RTS A (105)
RTS B
DTR A (108)
DTR B
CTS A (106)
CTS B
TM A (142)
SGND (102)
SHIELD (101)
18
2
14
24
11
15
12
17
9
3
1
4
19
20
23
6
22
8
10
5
13
21
7
16
25
1343 TA01
DB-25 CONNECTOR
LTC1344
D1
D3
D4
R1
R3
R4
R2
TXC A (114)
TXC B
RL A (140)
DCD A (109)
DCD B
DSR A (107)
DSR B
FEATURES
DESCRIPTIO
U
APPLICATIO S
U
TYPICAL APPLICATIO
U
2
LTC1343
ABSOLUTE
M
AXI
M
U
M
RATINGS
W
W
W
U
PACKAGE/ORDER I
N
FOR
M
ATIO
N
W
U
U
ORDER PART
NUMBER
T
JMAX
= 150
°
C,
JA
= 65
°
C/ W
Consult factory for Military grade parts.
(Note 1)
Supply Voltage ....................................................... 6.5V
Input Voltage
Transmitters ........................... 0.3V to (V
CC
+ 0.3V)
Receivers ............................................... 18V to 18V
Logic Pins .............................. 0.3V to (V
CC
+ 0.3V)
Output Voltage
Transmitters ................. (V
EE
0.3V) to (V
DD
+ 0.3V)
Receivers ................................ 0.3V to (V
CC
+ 0.3V)
Logic Pins .............................. 0.3V to (V
CC
+ 0.3V)
V
EE
........................................................ 10V to 0.3V
V
DD
....................................................... 0.3V to 10V
Short-Circuit Duration
Transmitter Output ..................................... Indefinite
Receiver Output .......................................... Indefinite
V
EE
.................................................................. 30 sec
Operating Temperature Range
LTC1343C .............................................. 0
°
C to 70
°
C
LTC1343I ........................................... 40
°
C to 85
°
C
Storage Temperature Range ................ 65
°
C to 150
°
C
Lead Temperature (Soldering, 10 sec)................. 300
°
C
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
TOP VIEW
GW PACKAGE
44-LEAD PLASTIC SSOP
44
43
42
41
40
39
38
37
36
35
34
33
32
31
30
29
28
27
26
25
24
23
V
DD
C1
+
PWRV
CC
C1
D1
D2
D3
V
CC
D4
D4EN
INVERT
R1EN
R1O
R2O
R3O
R4O
M0
M1
M2
CTRL/CLK
DCE/DTE
LATCH
C2
+
C2
V
EE
PGND
GND
D1 A
D2 A
D2 B
D3 A
D3 B
D4 A
D4 B
R1 A
R1 B
R2 A
R2 B
R3 A
R3 B
R4 A
423 SET
EC
LB
D2
D3
D1
D4
R1
R2
R3
R4
CHARGE PUMP
LTC1343CGW
LTC1343IGW
ELECTRICAL CHARACTERISTICS
SYMBOL
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
Supplies
I
CC
V
CC
Supply Current (DCE Mode,
V.10 Mode, No Load
12
mA
All Digital Pins = GND or V
CC
)
V.10 Mode, Full Load
q
80
150
mA
RS530, RS530-A, X.21 Modes, No Load
80
mA
RS530, RS530-A, X.21 Modes, Full Load
q
160
200
mA
V.35 Mode, No Load
20
mA
V.35 Mode, Full Load
q
115
160
mA
V.28 Mode, No Load
20
mA
V.28 Mode, Full Load
q
30
90
mA
No-Cable Mode
q
0.05
1
mA
P
D
Internal Power Dissipation (DCE Mode,
V.10 Mode, Full Load
400
mW
All Digital Pins = GND or V
CC
)
RS530, RS530-A, X.21 Modes, Full Load
680
mW
V.35 Mode, Full Load
500
mW
V.28 Mode, Full Load
150
mW
V
+
Positive Charge Pump Output Voltage
Any Mode, No Load
q
8.5
9.1
V
V.28 Mode, with Load
q
8.0
7.0
V
V
Negative Charge Pump Output Voltage
V.28 Mode, Full Load
q
7.8
8.4
V
V.35 Mode, Full Load
q
5.8
6.7
V
40
°
C
T
A
85
°
C
q
5.5
V
V.10, RS530, RS530A, X.21 Modes, Full Load
q
5.0
6.1
V
40
°
C
T
A
85
°
C
q
4.8
V
The
q
denotes specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25
°
C. V
CC
= 5V (Notes 2, 3)
3
LTC1343
ELECTRICAL CHARACTERISTICS
The
q
denotes specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25
°
C. V
CC
= 5V (Notes 2, 3)
SYMBOL
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
t
r
Supply Rise Time
No-Cable Mode or Power-Up to Turn On
2
ms
Logic Inputs and Outputs
V
IH
Logic Input High Voltage
q
2
V
V
IL
Logic Input Low Voltage
q
0.8
V
I
IN
Logic Input Current
q
±
10
µ
A
V
OH
Output High Voltage
I
O
= 4mA
q
3
4.5
V
V
OL
Output Low Voltage
I
O
= 4mA
q
0.3
0.8
V
I
OSR
Output Short-Circuit Current
0V
V
O
V
CC
, 0
°
C
T
A
70
°
C
q
60
60
mA
0V
V
O
V
CC
, 40
°
C
T
A
85
°
C
q
70
70
mA
I
OZR
Three-State Output Current
M0 = M1 = M2 = V
CC
, 0V
V
O
V
CC
±
1
µ
A
V.11 Driver
V
OD
Differential Output Voltage
Open Circuit, R
L
= 1.95k
q
±
6
V
R
L
= 50
(Figure 1),
q
±
2
V
V
OD
at 50
> 1/2 V
OD
at R
L
= 1.95k
V
OD
Change in Magnitude of Differential
R
L
= 50
(Figure 1)
q
0.2
V
Output Voltage
V
OC
Common Mode Output Voltage
R
L
= 50
(Figure 1)
q
3.0
V
V
OC
Change in Magnitude of Common Mode
R
L
= 50
(Figure 1)
q
0.2
V
Output Voltage
I
SS
Short-Circuit Current
0.25V
V
O
0.25V, Power Off or
±
150
mA
No-Cable Mode or Driver Disabled
I
OZ
Output Leakage Current
0.25V
V
O
0.25V, Power Off or
q
±
0.01
±
100
µ
A
No-Cable Mode or Driver Disabled
t
r
, t
f
Rise or Fall Time
(Figures 2, 6)
q
4
13
25
ns
t
PLH
Input to Output
(Figures 2, 6), 0
°
C
T
A
70
°
C
q
25
55
80
ns
(Figures 2, 6), 40
°
C
T
A
85
°
C
q
25
55
90
ns
t
PHL
Input to Output
(Figures 2, 6), 0
°
C
T
A
70
°
C
q
25
55
80
ns
(Figures 2, 6), 40
°
C
T
A
85
°
C
q
25
55
90
ns
t
Input to Output Difference,
t
PLH
t
PHL
(Figures 2, 6), 0
°
C
T
A
70
°
C
q
0
3
17
ns
(Figures 2, 6), 40
°
C
T
A
85
°
C
q
0
3
25
ns
t
SKEW
Output to Output Skew
(Figures 2, 6)
3
ns
V.11 Receiver
V
TH
Input Threshold Voltage
7V
V
CM
7V, 0
°
C
T
A
70
°
C
q
0.2
0.2
V
7V
V
CM
7V, 40
°
C
T
A
85
°
C
q
0.3
0.3
V
V
TH
Input Hysteresis
7V
V
CM
7V, 0
°
C
T
A
70
°
C
q
15
40
mV
7V
V
CM
7V, 40
°
C
T
A
85
°
C
q
60
mV
I
IN
Input Current (A, B)
10V
V
A, B
10V
q
±
0.50
mA
R
IN
Input Impedance
10V
V
A, B
10V
q
20
32
k
t
r
, t
f
Rise or Fall Time
(Figures 2, 7)
15
ns
t
PLH
Input to Output
(Figures 2, 7), CTRL = GND, 0
°
C
T
A
70
°
C
q
35
80
115
ns
CTRL = V
CC
, 0
°
C
T
A
70
°
C
400
ns
(Figures 2, 7), CTRL = GND, 40
°
C
T
A
85
°
C
q
25
80
130
ns
CTRL = V
CC
, 40
°
C
T
A
85
°
C
400
ns
4
LTC1343
ELECTRICAL CHARACTERISTICS
The
q
denotes specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25
°
C. V
CC
= 5V (Notes 2, 3)
SYMBOL
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
t
PHL
Input to Output
(Figures 2, 7), CTRL = GND, 0
°
C
T
A
70
°
C
q
35
80
115
ns
CTRL = V
CC
, 0
°
C
T
A
70
°
C
400
ns
(Figures 2, 7), CTRL = GND, 40
°
C
T
A
85
°
C
q
25
80
130
ns
CTRL = V
CC
, 40
°
C
T
A
85
°
C
400
ns
t
Input to Output Difference,
t
PLH
t
PHL
(Figures 2, 7), 0
°
C
T
A
70
°
C
q
0
5
17
ns
(Figures 2, 7), 40
°
C
T
A
85
°
C
q
0
5
25
ns
V.35 Driver
V
OD
Differential Output Voltage
Open Circuit
6.0
V
With Load, 4.0V
V
CM
= 4.0V (Figure 3)
q
±
0.44
±
0.55
±
0.66
V
I
OH
Transmitter Output High Current
V
A, B
= 0V
q
12.6
11
9.4
mA
I
OL
Transmitter Output Low Current
V
A, B
= 0V
q
9.4
11
12.6
mA
I
OZ
Transmitter Output Leakage Current
0.25V
V
A, B
0.25V
q
±
0.01
±
100
µ
A
t
r
, t
f
Rise or Fall Time
(Figures 3, 6)
5
ns
t
PLH
Input to Output
(Figures 3, 6), 0
°
C
T
A
70
°
C
q
25
45
75
ns
(Figures 3, 6), 40
°
C
T
A
85
°
C
q
25
45
90
ns
t
PHL
Input to Output
(Figures 3, 6), 0
°
C
T
A
70
°
C
q
25
45
75
ns
(Figures 3, 6), 40
°
C
T
A
85
°
C
q
25
45
90
ns
t
Input to Output Difference,
t
PLH
t
PHL
(Figures 3, 6), 0
°
C
T
A
70
°
C
q
0
5
17
ns
(Figures 3, 6), 40
°
C
T
A
85
°
C
q
0
5
25
ns
t
SKEW
Output to Output Skew
(Figures 3, 6)
4
ns
V.35 Receiver
V
TH
Differential Receiver Input
2V
(V
A
+ V
B
)/2
2V (Figure 3)
q
0.2
0.2
V
Threshold Voltage
V
TH
Receiver Input Hysteresis
2V
(V
A
+ V
B
)/2
2V (Figure 3)
q
11
40
mV
I
IN
Receiver Input Current (A, B)
10V
V
A, B
10V
q
±
0.50
mA
R
IN
Receiver Input Impedance
10V
V
A, B
10V
q
20
32
k
t
r
, t
f
Rise or Fall Time
(Figures 3, 7)
15
ns
t
PLH
Input to Output
(Figures 3, 7), 0
°
C
T
A
70
°
C
q
80
115
ns
(Figures 3, 7), 40
°
C
T
A
85
°
C
q
80
130
ns
t
PHL
Input to Output
(Figures 3, 7), 0
°
C
T
A
70
°
C
q
100
115
ns
(Figures 3, 7), 40
°
C
T
A
85
°
C
q
100
130
ns
t
Input to Output Difference,
t
PLH
t
PHL
(Figures 3, 7), 0
°
C
T
A
70
°
C
q
4
17
ns
(Figures 3, 7), 40
°
C
T
A
85
°
C
q
4
25
ns
V.10 Driver
V
O
Output Voltage
Open Circuit, R
L
= 3.9k
±
4.0
±
6.0
V
R
L
= 450
(Figure 4)
±
3.6
V
V
O
at 450
> 0.9 V
O
at R
L
= 3.9k
Driver 1 Only
I
SS
Short-Circuit Current
V
O
= GND; EIA-530, X.21, EIA-530-A Modes
±
150
mA
I
OZ
Output Leakage Current
0.25V
V
O
0.25V, Power Off or
q
±
0.1
±
100
µ
A
No-Cable Mode or Driver Disabled
t
r
, t
f
Rise or Fall Time
(Figures 4, 8), R
L
= 450
, C
L
= 100pF
R
423SET
= 100k
4
µ
s
t
PLH
Input to Output
(Figures 4, 8), R
L
= 450
, C
L
= 100pF
R
423SET
= 100k
8
µ
s
t
PHL
Input to Output
(Figures 4, 8), R
L
= 450
, C
L
= 100pF
R
423SET
= 100k
8
µ
s
5
LTC1343
V
DD
(Pin 1): Generated Positive Supply Voltage for
RS232. Connect a 1
µ
F capacitor to ground.
C1
+
(Pin 2): Capacitor C1 Positive Terminal. Connect a
1
µ
F capacitor between C1
+
and C1
.
PWRV
CC
(Pin 3): Positive Supply for the Charge Pump.
4.75V
PWRV
CC
5.25V. Tie to V
CC
(Pin 8) and bypass
with a 1
µ
F capacitor to ground.
PI
N
FU
N
CTIO
N
S
U
U
U
C1
(Pin 4): Capacitor C1 Negative Terminal.
D1 (Pin 5): TTL Level Driver 1 Input.
D2 (Pin 6): TTL Level Driver 2 Input.
D3 (Pin 7): TTL Level Driver 3 Input. Becomes a CMOS
level output when the chip is in the echoed clock mode
(EC = 0V).
Note 1: Absolute Maximum Ratings are those beyond which the safety of a
device may be impaired.
Note 2: All currents into device pins are positive; all currents out of device
are negative. All voltages are referenced to device ground unless otherwise
specified.
Note 3: All typicals are given for V
CC
= 5V, C1 = C2 = C
VCC
= C
VDD
= 1
µ
F,
C
VEE
= 3.3
µ
F tantalum capacitors and T
A
= 25
°
C.
ELECTRICAL CHARACTERISTICS
The
q
denotes specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25
°
C. V
CC
= 5V (Notes 2, 3)
SYMBOL
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
V.10 Receiver
V
TH
Receiver Input Threshold Voltage
0
°
C
T
A
70
°
C
q
0.2
0.2
V
7V
V
CM
7V, 40
°
C
T
A
85
°
C
q
0.3
0.3
V
V
TH
Receiver Input Hysteresis
q
11
50
mV
I
IN
Receiver Input Current
10V
V
A
10V
q
±
0.50
mA
R
IN
Receiver Input Impedance
10V
V
A
10V
q
20
30
k
t
r
, t
f
Rise or Fall Time
(Figures 5, 9)
15
ns
t
PLH
Input to Output
(Figures 5, 9)
350
ns
t
PHL
Input to Output
(Figures 5, 9)
350
ns
V.28 Driver
V
O
Output Voltage
Open Circuit
±
10
V
R
L
= 3k (Figure 4)
q
±
5
7.6
V
I
SS
Short-Circuit Current
V
O
= GND
q
±
150
mA
I
OZ
Output Leakage Current
0.25V
V
O
0.25V, Power Off or
q
±
0.01
±
100
µ
A
No-Cable Mode or Driver Disabled
SR
Slew Rate
(Figures 4, 8), R
L
= 3k, C
L
= 2500pF
q
4.0
30.0
V/
µ
s
t
PLH
Input to Output
(Figures 4, 8), R
L
= 3k, C
L
= 2500pF
q
1.6
2.5
µ
s
t
PHL
Input to Output
(Figures 4, 8), R
L
= 3k, C
L
= 2500pF
q
1.6
2.5
µ
s
V.28 Receiver
V
THL
Input Low Threshold Voltage
q
1.4
0.8
V
V
TLH
Input High Threshold Voltage
q
2.0
1.4
V
V
TH
Receiver Input Hysteresis
q
0.1
0.4
1.0
V
R
IN
Receiver Input Impedance
15V
V
A
15V
q
3
5
7
k
t
r
, t
f
Rise or Fall Time
(Figures 5, 9)
15
ns
t
PLH
Input to Output
(Figures 5, 9), CTRL = 0V
110
ns
CTRL = V
CC
q
330
800
ns
t
PHL
Input to Output
(Figures 5, 9), CTRL = 0V
170
ns
CTRL = V
CC
q
480
800
ns
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